Engineering Commons^™

Organic Geochemistry Of The Jurassic Tar-Rich Coal In Northern Shaanxi Province, Zhang Ning, Xu Yun, Qiao Junwei, Ning Shuzheng

Coal Geology & Exploration

The organic geochemical characteristics of tar-rich coal are of great significance to study the paleosedimentary environment and evolution of coal seams. Taking coal samples from 6 main coal seams of Yan’an Formation in Northern Shaanxi Province as the research object, this paper analyses the organic geochemical characteristics of coal seams by coal quality analysis and gas chromatography-mass spectrometry. The results showed that coal samples had a high abundance of chloroform asphalt "A" and a low saturated hydrocarbon/aromatic hydrocarbon ratios, characterized by the unimodal pattern of n-alkanes and dominated by medium chainsaturated hydrocarbons. The ratios of Pr/C₁₇, Ph/C_{18 …}

Occurrence Characteristics Of Carboniferous-Permian Tar-Rich Coal And Its Influencing Factors In Northern Shaanxi, Yao Zheng, Luo Qianzhou, Li Ning, Li Huabing, Wang Qiang, Gao Jun

Coal Geology & Exploration

The rational development of tar-rich coal is of great significance to promote clean and efficient utilization of coal, improve the independent guarantee ability of oil and gas, and achieve carbon emission peak and carbon neutrality. In order to find out the occurrence characteristics of tar-rich coal in the typical mining areas of Carboniferous-Permian coalfield in Northern Shaanxi, based on coal exploration data and sample test results, this paper compares the tar yield of mineable coal seams, summarizes the spatial-temporal distribution rules of tar-rich coal, and discusses the occurrence influential factors. The results show that the average tar yield of mineable …

Gas Drainage Borehole Completion Technology Of Directional Long Hole Drilling With Negative Angle, Ma Zan, Chen Dongdong, Xie Hengxing, Chen Tianzhu, Wang Bin, Jia Bingyi

Coal Geology & Exploration

Pre-drainage of coal seam gas with directional long boreholes is an effective technical means to achieve advanced control of coal mine gas area. Affected by mining deployment, negative-angle boreholes(downward holes) are widely used in production. Medium-hard coal seams have good porosity and usually do not require hole protection. However, the existing conventional methods can not effectively solve the problem of water accumulation in negative angle long boreholes. This paper takes the downward long boreholes in the No. 9 medium-hard coal seam of Longfeng Coal Mine in Guizhou as the research object. Two sets of directional long boreholes are constructed in …

The Concealed Small Faults Detection Based On Gas Drainage Boreholes Along And Cross The Coal Seam, Xue Honglai, Wen Zhe

Coal Geology & Exploration

The faults have great influence on coal and gas outburst disasters, and accurate detection of faults location is very important to prevent such disasters. At present, large number of gas drainage boreholes were drilled in coal mines, but the geological information contained in these boreholes is not fully paid attention to, thus the method to detect concealed faults by gas-drainage boreholes was proposed. In this paper, by establishing a mathematical model for fault detection based on gas drainage drilling, a three-dimensional coordinate of fault planes and coal seam floors is calculated, and basic parameters such as fault location, drop, attitude …

Quantitative Study Of 3d Numerical Simulation On Optimizing Borehole Layout Spacing Of Gas Drainage, Chen Yuexia, Chu Tingxiang, Chen Peng, Tang Yang

Coal Geology & Exploration

In order to optimize the spacing of boreholes and realize efficient drainage, based on the fluid solid coupling model, a three-dimensional geometric model was established to make it closer to the field reality, the gas drainage processes of a coal mine with different borehole spacing were simulated using COMSOL software. The results show that: the effective drainage area was visualized by the three-dimensional diagram of the isobaric surface with gas pressure of 0.74 MPa, and the influence of borehole spacing on the extraction efficiency was discussed. The results show that: the effective extraction radius is about 1.5 m during gas …

An Advanced Co2 Gas-Phase Fracturing Technology For Efficient Methane Drainage, Outburst Prevention And Excavation In Outburst Coal Seam, Yang Baige, Zhang Junsheng, Linghu Jianshe, Cao Yunxing

Coal Geology & Exploration

Coal and gas outburst in coal mines is a serious disaster in China. Although the disaster has been reduced significantly over the past 10 years, vicious accidents still occure, causing serious losses to the lives of miners and the safety of coal mines. The current applied technologies for outburst prevention and control include hydraulic fracturing, hydraulic slitting, hydraulic flushing, deep hole blasting, intensive drilling, etc., which have solved the outburst problem and safe excavation in some degrees. Nevertheless, the above-mentioned technologies could not solve the problems of safety excavation in the high gas content and low permeability outburst coal seams. …

Effect Of Load On Adsorption Characteristics Of Remolded Coal, Dai Juhua, Wang Zhaofeng, Li Xuechen, Li Yanfei, Yue Jiwei

Coal Geology & Exploration

In view of the difficulty in preparing the coal with broken soft structure intact, it needs to be processed into remolded coal. In order to study the influence of suppression loads on the physical characteristics of coal, the micro-pore structure and adsorption characteristics of remolded coal under different molding loads were discussed based on the pore test experiment of low temperature liquid nitrogen and the methane adsorption experiment of high pressure capacity method. The results show that: The pore volume of micropores and pores decreases slightly with the increase of molding load, the specific surface area increases slightly with the …

Hydrate Reservoir Physical Properties Response And High-Pressure Gas-Water Reverse Penetration During Deepwater Oil And Gas Cementing, Zheng Mingming, Wang Xiaoyu, Zhou Kerui, Wang Kai, Wang Zhilin, Dong Gang, Wei Meng, Liu Tianle, Jia Dongyan

Coal Geology & Exploration

Well cementing is an important stage during the process of energy extraction. When deep-water oil and gas cementing encounters hydrate formations, the hydration heat of cementing slurry will cause hydrate decomposition in the reservoir near the borehole wall and reverse penetration of high-pressure gas-water. To reduce and avoid the adverse effects of hydrate decomposition, it is critical to clarify the physical response of hydrate reservoirs and the law of high-pressure gas-water reverse penetration under different cementing conditions. In this paper, a two-dimensional cementing numerical model is established according to the SH2 exploration well of GMGS-1 project in Shenhu area in …

The Development Of A Single-Component Non-Cable Seismograph In Underground Coal Mines, Li Yuan

Coal Geology & Exploration

In-seam wave seismic exploration, featured in wide detection range and high accuracy, plays an increasingly important role in the refined exploration of coal geological structures. However, most seismic exploration equipment is bulky, with a large number of cables are laid in construction, leading to low efficiency and high construction cost. This seriously restricts the development of high-precision in-seam wave seismic exploration technology in underground coal mines. Based on the design concept of nodal seismograph, the moving coil geophone is integrated into a complete cavity with the acquisition and control circuit, the time precision keeping circuit and the power supply circuit. …

Green Detection Method Of Coal Burning Area In Northern Shaanxi Based On Microbial Hydrocarbon Detection Technology, Duan Zhonghui, Ma Li, Hao Chun, Wang Lengyao, Mei Hai

Coal Geology & Exploration

Coal seams contain all kinds of light hydrocarbons. When coal seams are burned, the integrity of overlying strata is destroyed, which provides a good channel for hydrocarbon escape from the coal seam. This process conforms to the principle of light hydrocarbon microseepage. Then, microseepage associated microbial hydrocarbon detection technology is introduced to test its recognition ability of coal seam burning area. In Haojialiang Coal Mine of Jurassic Coalfield in northern Shaanxi, two survey lines were tested and butane bacteria was selected as microbial detection index. After microbial analysis process such as soil sampling, microbial culture, and colony count, combined with …

Feasibility Study On The Principle Of Punching-Shearing Composite Rock Fragmentation Mode Of Connecting Holes In Rock Strata, Wang Chuanliu

Coal Geology & Exploration

Replacing roadway with borehole is an important research direction of underground coal mine drilling technology, which has the advantages of high efficiency and low cost. However, in the construction of large diameter connecting holes in rock strata, the multi-stage reaming method has such problems as long lifting and drilling time and low efficiency of hole formation. This paper proposes the principle of punching-shearing composite rock fragmentation through structural and technological innovation without changing the configuration of drilling equipment. It is a creative combination of punching rock fragmentation of high-pressure water-impactor-inner bit rock and shearing rock fragmentation of drilling rig-drilling pipe-outer …

Analysis On The Deployment Of Mining Research Supported By The Grant Program Of Deep Resources Exploration And Mining, Fan Jun, Zhang Jialin, Qin Yuan, Wang Hao, Gao Yanan, Pei Yongzhi

Coal Geology & Exploration

The Deep Resources Exploration and Mining(DREAM) grant program, within the framework of The National Key Research and Development Program grants, is a pillar to implement China’s science and technology strategy in the area of deep resources exploitation. To tackle the insufficient of theories and technologies for the 1000-meter-deep mining, a section of mining, covering the research of basic theories, general technologies and application demonstration, was arranged in the layout of DREAM under the principle of "whole chain design, integrated implementation". In the aspect of basic research, DREAM mainly focused on the deep rock mechanics and mining theory, such as the …

Experimental Study On Multi-Scale Pore Structure Characteristics Of Tar-Rich Coal In Yushenfu Mining Area, Shen Yanjun, Wang Xu, Zhao Chunhu, Wang Shengquan, Guo Chen, Shi Qingmin, Ma Wen

Coal Geology & Exploration

Extracting oil and refining gas from oil-rich coal is an important measure to make up for the shortage of oil and gas supply in China. The research on pore development characteristics and permeability of tar-rich coal will help to better develop and utilize tar-rich coal. Taking the tar-rich coal in Yushenfu mining area as the research object, this paper studies the multi-scale pore structure and the whole segment pore characterization of tar-rich coal by such methods as low-temperature liquid nitrogen adsorption, mercury intrusion porosimetry, nuclear magnetic resonance and gas permeability measurement method. Based on the test results of multi-scale pore …

Prediction Model Of Coalbed Methane Content Based On Well Logging Parameter Optimization, Chen Tao, Zhang Zhansong, Zhou Xueqing, Guo Jianhong, Xiao Hang, Tan Chenyang, Qin Ruibao, Yu Jie

Coal Geology & Exploration

With the development of coalbed methane(CBM) exploration, higher accuracy of CBM content prediction is required. Based on the response characteristics of CBM logging, the correlation between logging parameters and gas content is analyzed, and the optimization strategy of logging parameters by combining MIV technology with LSSVM is proposed. The optimal logging parameters are selected as the input independent variables of network modeling, and the core parameters of LSSVM(Least Squares Support Vector Machine) network are optimized by particle swarm optimization. Finally, a set of MIV-PSO-LSSVM model suitable for CBM content prediction is constructed. The prediction performances of LSSVM, PSO-LSSVM, MIV-LSSVM, MIV-PSO-LSSVM …

Modeling Of Bearing Voltage In Electric Machines Based On Electromagnetic Fea And Measured Bearing Capacitance, Peng Han, Greg Heins, Dean Patterson, Mark Theile, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

Bearing voltages and associated bearing currents in electric machines driven by pulsewidth modulation converters with high switching frequencies and high dv/dt can cause premature bearing failures. This article proposes a new modeling approach for the prediction of steady-state and transient bearing voltages based on two-dimensional (2-D) electromagnetic finite element analysis with coupled external circuits using measured bearing capacitance values. The distributed-element external circuit was employed mainly to take into account the influence of wire distribution and frequency dependency, which are typically neglected by traditional equivalent circuits. The developed model was then used to simulate bearing voltages for various scenarios and …

Analysis Of Interlayer Interference In Combined Development Of Coalbed Methane Wells And Discussion On Combined Production Methods：A Case Study Of Shoushan No.1 Coal Mine In Pingdingshan, Xu Yaobo

Coal Geology & Exploration

The combined development of multiple coal seams is a key technology to increase the production of single CBM wells. However, in engineering practice, most coal seams have interlayer interference problems, resulting in an insignificant increase in combined development gas production. In order to improve the gas production and development efficiency of combined development in coalbed methane wells, taking the combined production of coalbed methane in the No.4-2 coal seam and the No.2-1 coal seam of the Shoushan No.1 Coal Mine in Pingdingshan as an example, this paper analyses the influence factors and interference rules of interlayer interference, and proposes the …

Model Tests On The Red Clay Foundation Reinforced By The Natural Coir Fiber, Li Liangyong, Ma Weidi, Xie Peng, Cao Qian, Huang Ruilong

Coal Geology & Exploration

Due to the advantages of low cost, good seismic performance, simple construction, etc., reinforcement method has become a common method of foundation improvement. However, the geosynthetic used in the reinforcement method is not natural and environmentally friendly. To solve this problem, the natural coir fiber is used to reinforce the red clay foundation in this paper. The effect of the coir fiber reinforcement depth on the deformation and bearing capacity of the red clay foundation is studied through load tests. The distribution law of the earth pressure along depth is analyzed. The results show that the load bearing ratio increases …

Application And Development Of Permanent Magnet Torque Motor In Down-Hole Tools For Oil And Gas Drilling And Production, Li Wei, Deng Lang, Zou Xing, Xia Yang, Chen Xi

Coal Geology & Exploration

Permanent magnet torque motor is a kind of a power driving device with great development potential. It has several advantages, such as high torque density, fast response speed, strong overload capacity, high efficiency and energy saving, therefore, it possesses wide application prospects in many fields in both industrial production and daily life and so on. In view of the current application overview and technical requirements of permanent magnet torque motors in oil and gas drilling and production down-hole intelligent tools, firstly, this paper briefly introduces the structure composition and working principle of permanent magnet torque motor. Then, it elaborates the …

High Speed Switching For Plasma Based Electroporation, Shivangi Sharma

USF Tampa Graduate Theses and Dissertations

Ever since mankind has started identifying the diseases, extensive work has been done, and pathologies are written identifying the cure for them. As technology progressed, the development in the field of pathologies also did. Thus, finding innovative and efficient ways to get the ‘cure’. With the advancement in drugs, the delivery methods for these drugs also have advanced. One such delivery method is gene therapy. This method is beneficial when genes are to be used to prevent diseases.

Gene therapy has been proven effective for treating a wide range of conditions, such as cancer, heart diseases, and diabetes. Gene therapy …

Analysis And Modeling Of Strategic Interactions In Health Systems To Improve Patient Care Access, Jorge A. Acuña Melo

USF Tampa Graduate Theses and Dissertations

Affordable health care access that provides well-coordinated and high-quality services on time is a goal that governments and health organizations strive for. Regrettably, most countries deal with access problems that affect the population's health, such as long waiting lists for specialized medical services, overcrowding of emergency departments, and high health prices. In the present doctoral dissertation, I model and analyze the strategic interactions that inhabit the health system machinery to uncover possible structural problems that led to the aforementioned issues. The study involves operation research, data science, and game theory techniques to address the health care access predicament.

Each research …

Water Inrush Mechanism Of Thick Alluvium Aquifer With High Pressure Based On The “Bidirectional Fractures” Model In Huainan And Huaibei Mining Area, Liu Qimeng, Liu Yu, Xie Zhigang, Bai Hanying, Fu Xiang, Miao Changjun

Coal Geology & Exploration

The coal reserves under Quaternary thick alluvium with high pressure are huge in Huainan and Huaibei Mining Areas. In the process of increasing the upper limit mining near the alluvium, water inrush accidents often occur. However, it is difficult to reasonably explain the mechanism of such accidents by using the traditional aupper three zonesa theory. In this paper, the hydrogeological and engineering geological conditions of thick alluvium with high pressure are analyzed, and the abidirectional fracturesa model is established. Laboratory experiment, numerical simulation, theoretical analysis, and engineering application inspection are used to study the development law of downward infiltration zone …

Classification Method Of Coal And Rock Drillability Based On Mechanical Specific Energy Theory, Xie Zhijiang, Chang Xue, Yang Lin, Pi Yangjun

Coal Geology & Exploration

The drillability classification of the surrounding rock during the drilling process of coal mine gas drainage through the Mechanical Specific Energy(MSE) can provide a basis for the drilling rig to adjust the drilling parameters. Aiming at the problems of difficulty and low efficiency of manual layer identification in the process of gas drainage and drilling, a coal and rock drillability classification method based on MSE as the drillability evaluation index combined with Extreme Learning Machine(ELM) is proposed. A simulation model of PDC bit crushing rock was established by ABAQUS, and the changing law of drilling speed and MSE in the …

Research On The Evolution Law Of Roadway Surrounding Rock Fissure Based On Fractal Dimension, Ding Wanqi, Ma Zhenqian, Zu Ziyin, Xie Hongfei, Yang Wei, Chen Chuan

Coal Geology & Exploration

To explore the evolution law of surrounding rock fissures under the influence of horizontal stress and dynamic disturbance in argillaceous roadways, the deformation and failure characteristics of argillaceous roadways, the evolution law of surrounding rock fissures and the fractal evolution characteristics of surrounding rock fissures under dynamic disturbance are studied by such methods as field investigation, numerical simulation and fractal theory analysis, with the 226 track gate of Shanjiaoshu Mine in Panzhou City as the engineering background. The results show that before dynamic disturbance, the expansion range of fracture zone and plastic zone of roadways gradually increases with the increase …

Creating A Field-Wide Forage Canopy Model Using Uavs And Photogrammetry Processing, Cameron Minch, Joseph S. Dvorak, Joshua J. Jackson, Stuart Tucker Sheffield

Biosystems and Agricultural Engineering Faculty Publications

Alfalfa canopy structure reveals useful information for managing this forage crop, but manual measurements are impractical at field-scale. Photogrammetry processing with images from Unmanned Aerial Vehicles (UAVs) can create a field-wide three-dimensional model of the crop canopy. The goal of this study was to determine the appropriate flight parameters for the UAV that would enable reliable generation of canopy models at all stages of alfalfa growth. Flights were conducted over two separate fields on four different dates using three different flight parameters. This provided a total of 24 flights. The flight parameters considered were the following: 30 m altitude with …

The Origin Of Coal Measure Breccia In Jinggong No.3 Coal Mine, Pingshuo, Shanxi, Shi Yanqiang

Coal Geology & Exploration

The genesis and occurrence of coal measure breccia in Jinggong No.3 Coal Mine of Pingshuo are special and closely related to the coal seams. Through core observation of supplementary drilling, combined with regional geology and analysis of previous drilling data, the composition, structure and structural characteristics of breccia in the study area are described in detail, and the horizon, thickness and distribution of breccia are delineated. It is found that the composition of breccia in Jinggong No.3 Coal Mine of Pingshuo is complex, and the size of breccia is different. The maximum diameter of mudstone is more than 1.20 m, …

Experimental Study On The Influence Of Coal-Based Co2 Geological Storage On Roof Fracture Conductivity, Zhu Shiliang, Shao Liwei, Zhou Xiaozhi, Cao Yutong, Zhang Kun, Wang Jiandong

Coal Geology & Exploration

Coal-based CO₂ geological storage is an important way to reduce greenhouse gas emissions, but there is also a safety risk of underground CO₂ leakage. In order to evaluate the safety of coal-based CO₂ geological storage, the roof samples of No.3 coal seam in Hudi Coal Mine, southern Qinshui Basin were collected, and the changes of artificial fracture morphology, whole rock mineral composition and CO₂ conductivity of columnar samples in "CO₂-H₂O-Rock" reaction were studied by simulation experiments. The results show that calcite vein dissolution, secondary mineral filling and external effective stress jointly affect …

Research On Wireline Sealed Coring Equipment And Technology For Coalbed Methane Content Determination, Long Weicheng, Sun Siqing

Coal Geology & Exploration

Coalbed methane content is an important technical parameter for the development and utilization of coalbed methane resources and the prevention and control of mine gas. In order to solve the problem of deviation of coalbed methane content measurement results caused by inaccurate estimation of coal core loss gas volume in the process of surface well coalbed methane content determination, the wireline sealing coring device for surface well coal seam is developed, and the wireline sealing coring technology for surface well coal seam is proposed. The upper end of the coal seam wireline sealing coring device is designed with wireline fishing …

Surface Subsidence Control Technology Of Multi-Bed Separation Grouting, Ma Hewen

Coal Geology & Exploration

In order to enhance the injection ratio to meet the surface subsidence controlling requirements without obvious thick-and-hard strata in overburden for generating large-scale bed separation, the multi-bed separation grouting method is proposed in this paper. The scale model test is used to study the spatiotemporal evolution of overburden due to multi-bed separation grouting. The field measurements is proven that multi-bed separation grouting can successfully mitigate overburden failure and subsidence by increasing the boreholes number, and multi-bed separation grouting has successfully applied in Huaibei mining area. Filling masses with different diffusion radii are commonly formed in the different bed separation, which …

Mining Subsidence Analysis Of Gently Inclined Coal Seams Based On Flac3d And Dem Data, Gan Zhihui, Shang Hui, Du Rongjun, Zhan Huizhu

Coal Geology & Exploration

Shizuishan Mining Area in Ningxia Province is located in the western Yellow River. The subsidence of the mined-out area causes frequent surface ecological and environmental problems. The analysis of coal mining subsidence will play a positive role in environmental remediation the Yellow River Basin. Taking Shizuishan Coal Mine as an object to study the evolution characteristics of surrounding rock stress and displacement field of gently inclined coal seam, a three-dimensional numerical model of the gently inclined coal seam based on the numerical simulation software FLAC^3D was established. The variation of stress, plastic zone, and displacement in the surrounding rocks …

Variation Law And Influencing Mechanism Of Surface Movement Parameters In Shendong Mining Area, Zhou Tingting, Su Lijuan, Liu Hui, Zhu Xiaojun

Coal Geology & Exploration

The mining areas in western China generally have the characteristics of large reserves, shallow depth and simple overlying rock structure, and mining activities in such areas have a significant impact on the surface. In order to study the variation law of surface deformation and rock movement parameters in Shendong Mining Area, the dynamic deformation of the surface was studied based on the measured data of working face 22201 of Daliuta Coal Mine. Then the relationship between surface movement parameters and geological mining conditions were obtained from the measured data of 18 working faces in Shendong Mining Area, and the influence …